Modular network switches, associated structures, and associated methods of manufacture and use

ABSTRACT

Modular network switches and other computer systems are described herein. A modular network switch can include a latching device for installing and removing computer modules (e.g., line cards) from an associated cabinet or enclosure. The network switch can also include interconnected computer modules (e.g., line cards, fabric cards, control modules, etc.) that include circuit boards oriented parallel to the flow of cooling air through the cabinet in the absence of a backplane or midplane oriented perpendicular to the air flow. The absence of such backplanes and/or midplanes provides a more direct air flow path through the cabinet, thereby enabling a more efficient flow of cooling air and lower operating temperatures. Additionally, the network switch can include an orthogonal arrangement of data planes, control planes, and/or power planes that can be efficiently interconnected to increase operational speed and further facilitate the flow of cooling air through the computer cabinet.

CROSS-REFERENCE TO RELATED APPLICATION(S) INCORPORATED BY REFERENCE

The present application claims priority to and the benefit of U.S.Provisional Patent Application No. 62/335,000, filed May 11, 2016, andtitled MODULAR SWITCH, which is incorporated herein by reference in itsentirety.

TECHNICAL FIELD

The following disclosure relates generally to computer systems and, moreparticularly, to network switch architectures and associatedapparatuses, systems and methods.

BACKGROUND

Network switches (also known as a switching hubs, bridging hubs, MACbridges or simply “switches”) are computer networking devices thatconnect other devices together in a computer network. Network switchesare typically used in complex data networking environments to, forexample, interconnect various devices within one or more subnetworks.Some network switches use packet switching to receive, process, andforward data to destination devices. Switches can be used for electricalswitching, optical switching that enables signals in optical fibers orintegrated optical circuits to be selectively switched from one circuitto another, or a combination of electrical and optical switching.

Typical network switches include a plurality of circuit boards withassociated switch circuitry (e.g. line cards and fabric cards) that areinterconnected via backplane or midplane circuit boards within anenclosure. Although some cards include handles for manually removing thecards from the enclosure, conventional handles (particularly for opticalcards) do not have locking features to hold the cards in place.Additionally, such handles typically require manual manipulation toeject the cards from the enclosure.

As is known, line cards typically include a modular electronic circuitdesigned to fit on a separate printed circuit board (PCB) and interfacewith a data communications network, and can providetransmitting/receiving ports for a local area network (LAN) and/or awide area network (WAN). Fabric cards can include one or more switchelements for implementing the stages of the switch fabric. The linecards and fabric cards can be mounted to the backplane and/or midplanein a motherboard/daughterboard relationship in which the backplane ormidplane extends transversely across the enclosure. In this arrangement,the backplane/midplane is perpendicular to the flow of cooling airthrough the enclosure, and can block or otherwise impede the flow ofcooling air, resulting in relatively high operating temperatures thatcan reduce the longevity and/or performance of switch components.Another factor that can affect cooling is the efficiency of the airinlets and air outlets on the switch enclosure. Conventional networkswitches utilize fans to move cooling air through the enclosure andmaintain the electronic components at suitable operating temperatures.Typically, perforated sheet metal is used to form air inlet and outletvents on the front and back of the enclosure, respectively. Althoughsuch material can provide suitable covers for the enclosure, limitationson the size of the perforations limit the amount of air flow into theenclosure and can result in less than optimum cooling.

In conventional network switches, the central processing units (CPUs)are typically mounted to line cards. As a result, upgrading CPUs in aconventional switch generally requires removal and replacement of linecards to change out the CPUs. CPU technology, however, tends to advanceat a relatively quick pace, which can lead to relatively frequent linecard removal and replacement for CPU upgrades in conventional switches.In view of the shortcomings associated with conventional networkswitches, it would be advantageous to develop a network switch thatprovides, among other things, efficient cooling and relatively easycomponent replacement.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are front and rear isometric views, respectively, of acomputer system configured in accordance with an embodiment of thepresent technology.

FIG. 2 is an enlarged isometric view of a front portion of the computersystem of FIG. 1A illustrating a latch for retaining a computer modulein a computer cabinet in accordance with an embodiment of the presenttechnology.

FIG. 3A is an isometric view of the latch of FIG. 2, and FIGS. 3B-3D area series of partially exploded isometric views of the latch configuredin accordance with an embodiment of the present technology.

FIGS. 4A-4E are a series of isometric views illustrating operation ofthe latch of FIGS. 2-3D in accordance with an embodiment of the presenttechnology.

FIGS. 5A and 5B are front and rear isometric views, respectively, of thecomputer system 100 with a number of external panels removed forpurposes of illustrating the arrangement of various internal structuresand systems in accordance with an embodiment of present technology.

FIG. 6A is an isometric view of a control plane assembly configured inaccordance with an embodiment of the present technology, and FIG. 6B isa front view of the associated computer cabinet with a number ofelectronic components removed for purposes of illustration.

FIG. 7 is a schematic diagram illustrating one possible environment inwhich embodiments of the present technology can be implemented.

DETAILED DESCRIPTION

The following disclosure describes various embodiments of modularnetwork switches for use in, for example, highly-functioning datacomputing environments, such as server data computing environments, datacenters, etc. In some embodiments, a modular network switch configuredin accordance with the present technology can include a latchingapparatus for quickly and easily securing switch components (e.g., linecards, etc.) in a cabinet or other enclosure, and easily removing thecomponents for upgrade or replacement. In other embodiments, networkswitches configured in accordance with the present technology caninclude an orthogonal arrangement of internal components (e.g., dataplanes, control planes, and power planes, etc.). In these embodiments,the associated circuit boards are oriented parallel to a flow of coolingair through the switch cabinet, and the switch lacks a backplane,midplane, or other mounting structure (e.g., another circuit board)oriented perpendicular to the air flow in a blocking relationship. As aresult, the orthogonal arrangement enables a parallel flow of coolingair through the cabinet without the obstruction of a backplane ormidplane. This can result in lower component operating temperatures thanconventional switches having, e.g., backplanes or midplanes that blockfront-to-back air flow. In further embodiments, network switchesconfigured in accordance with the present technology can include adistributed central processing unit (CPU) design in which one or moreCPUs (and/or graphics processing units (GPU), or other digital computingprocessor) are positioned near the front side of the cabinet onindependent circuit boards so that they can be easily replaced and/orupgraded while the other components of the switch remain in place. Theforegoing are only some of the aspects of the various embodiments ofnetwork switches and other computer systems described herein, andfurther details describing these aspects are provided below.

Certain details are set forth in the following description and in FIGS.1-7 to provide a thorough understanding of various embodiments of thepresent technology. In other instances, well-known structures,materials, operations and/or systems often associated with networkswitches, circuit boards, electrical connectors, computer hardware, andassociated systems and methods are not shown or described in detail inthe following disclosure to avoid unnecessarily obscuring thedescription of the various embodiments of the technology. Those ofordinary skill in the art will recognize, however, that the presenttechnology can be practiced without one or more of the details set forthherein, or with other structures, methods, components, and so forth.

The terminology used below is to be interpreted in its broadestreasonable manner, even though it is being used in conjunction with adetailed description of certain examples of embodiments of thetechnology. Indeed, certain terms may even be emphasized below; however,any terminology intended to be interpreted in any restricted manner willbe overtly and specifically defined as such in this Detailed Descriptionsection.

The accompanying Figures depict embodiments of the present technologyand are not intended to be limiting of its scope. The sizes of variousdepicted elements are not necessarily drawn to scale, and these variouselements may be arbitrarily enlarged to improve legibility. Componentdetails may be abstracted in the Figures to exclude details such asposition of components and certain precise connections between suchcomponents when such details are unnecessary for a completeunderstanding of how to make and use the invention. Additionally, manyof the details, dimensions, angles and other features shown in theFigures are merely illustrative of particular embodiments of thedisclosure. Accordingly, other embodiments can have other details,dimensions, angles and features without departing from the spirit orscope of the present invention. In addition, those of ordinary skill inthe art will appreciate that further embodiments of the invention can bepracticed without several of the details described below. In theFigures, identical reference numbers identify identical, or at leastgenerally similar, elements. To facilitate the discussion of anyparticular element, the most significant digit or digits of anyreference number refers to the Figure in which that element is firstintroduced. For example, element 110 is first introduced and discussedwith reference to FIG. 1.

FIGS. 1A and 1B are front and rear isometric views, respectively, of acomputer system 100 configured in accordance with an embodiment of thepresent technology. In the illustrated embodiment, the computer system100 is a modular network switch, and is referred to herein as a “networkswitch 100” or simply “switch 100” for ease of reference. In otherembodiments, however, the computer system 100 and various embodiments ofthe technology described herein can be implemented in other types ofcomputer systems, including other types of switch systems, serversystems, etc. The computer system 100 includes an enclosure or cabinet102 having a front end 104 opposite an aft end 106. The cabinet 102 canbe constructed from, for example, sheet metal panels attached to a metalframework using methods and systems well known in the art.

Referring to FIG. 1A, a plurality of computer modules are installed inthe cabinet 102 proximate the front end 104. For example, the cabinet102 contains a plurality of line cards 108 (identified individually asline cards 108 a-d) which are arranged horizontally in a front portionof the cabinet 102. Each of the line cards 108 includes at least oneport 136 for receiving data from an external device in a network, and atleast one application-specific integrated circuit (ASIC) for data packetforwarding. As described in greater detail below, each of the line cards108 includes a first latch 110 a mounted to one side of the line card108, and a corresponding second latch 110 b mounted to an opposite sideof the line card 108. The latches 110 a and 110 b can be essentiallymirror images of each other, and can be used to install and retain eachof the line cards 108 in position within the cabinet 102. A number ofother computer modules are also installed in the cabinet 102 via thefront end 104. For example, a plurality of control modules 112(identified individually as control modules 112 a-112 j) are verticallyoriented side-by-side beneath the line cards 108. By way of exampleonly, the first control module 112 a and the tenth control module 112 jcan be chassis management modules (CMMs) that each carry one or moreCPUs for chassis management, and the second control module 112 b throughthe ninth control module 112 i can be system controller modules (SCMs)that each carry one or more CPUs for controlling operation of switchelements on the line cards 108 and/or the fabric cards (describedbelow). Each of the control modules 112 can be individually removed fromthe cabinet 102 by pulling on a corresponding handle 113 and withdrawingthe control module 112 from the front end 104. In other embodiments,other types of control modules and/or other types of computer componentscan be positioned in the cabinet 102 beneath the line cards 108.

In addition to the line cards 108 and the control modules 112, thecabinet 102 further includes a plurality of power units 116 a-dremovably installed next to each other beneath the control modules 112.The power units 116 can convert mains AC power to, for example,low-voltage regulated DC power for use by the switch components (e.g.,the line cards 108, the control modules 112, etc.). Each of the powerunits 116 can be individually removed from the cabinet 102 by pulling ona corresponding handle 117 to withdraw the power unit 116 from the frontend 104. In a further aspect of this embodiment, the network switch 100can additionally include a plurality of power inlets 114 a-d at thefront end 104 of the cabinet 102. In the illustrated embodiment, each ofthe power inlets 114 includes a receptacle which is covered by a movablecover that can be displaced so that an appropriate connector can beconnected to the receptacle in a known manner to receive mains AC foreach of the power units 116. For example, in one embodiment, the firstpower inlet 114 a can be electrically connected (via, e.g., a suitablewired connection) to the first power unit 116 a to receive AC power forthe first power unit 116 a. Similarly, the second power inlet 114 b canreceive AC power for the second power unit 116 b, and so on for thethird and fourth power inlets 114 c and d, respectively.

Referring next to FIG. 1B, it should be noted that the aft end 106 ofthe cabinet 102 also includes a plurality of power inlets 128(identified individually as power inlets 128 a-d). Like the power inlets114 described above with reference to FIG. 1A, each of the power inlets128 includes a receptacle configured to receive an appropriate powercord connector for providing facility AC power to the power units 116a-d (FIG. 1A). More specifically, in the illustrated embodiment, thepower inlet 128 a provides AC power (via, e.g., a suitable wiredconnection) to the first power unit 116 a, the second power inlet 128 bprovides AC power to the second power unit 116 b, and so on for thethird and fourth power inlets 128 c and d, respectively. In theforegoing manner, the switch 100 provides redundant power inlets 114 and128 that can accommodate a broad range of switch placement orientationsthat are not limited by the location of the power inlets.

In another aspect of this embodiment, the network switch 100 includes aplurality of air movers for moving cooling air along an air flow pathfrom front to back through the computer cabinet 102 as indicated by thearrows A. In the illustrated embodiment, the air movers are a pluralityof fan units 124 a-I which are carried toward the aft end 106 of thecabinet 102. Each of the fan units 124 can include an electric motor(not shown) that drives a corresponding fan (also not shown). The fanunits 124 can be arranged in four columns of three, in which each columnof three fan units 124 comprises a corresponding fan tray. As describedin more detail below, each of the fan trays can be operably connected toa corresponding fabric card oriented vertically within the aft portionof the cabinet 102. In operation, the fan units 124 draw air into thecomputer cabinet 102 via air inlets at the front end 104, and move theair through the computer cabinet in a generally linear direction fromfront to back as indicated by the arrows A, before the air exits thecabinet 102 via the outlets at the aft end 106. If needed, individualfan units 124 can be removed from the cabinet 102 by operation of acorresponding handle 125.

The air inlets at the front end 104 of the cabinet 102 are comprised ofa plurality of vents associated with the various computer modulesinstalled in the front portion of the cabinet 102. More specifically,each of the line cards 108 includes a face panel 130 having a pluralityof connector ports 136 surrounded by a perforated portion 118. Theperforated portion 118 includes a plurality of apertures that serve asair inlet vents into the computer cabinet 102. Similarly, each of thecontrol modules 112 includes a corresponding face panel 132 having aperforated portion 120 and one more connector ports 138. Each of thepower units 116 also includes a corresponding face panel 134 having acorresponding perforated portion 122. Accordingly, in the illustratedembodiment, each of the perforated portions 118, 120 and 122 includes aplurality of apertures that collectively form the air inlet vents intothe computer cabinet 102. The apertures can have, for example, hexagonalshapes arranged in a honeycomb pattern. In other embodiments, theapertures can have rectangular, round, and/or other shapes in otherregular and/or irregular patterns. In some embodiments the perforatedface panels of the line cards 108, the control modules 112, and thepower units 116 can be made from aluminum, such as aluminum extrusionsthat are machined to provide the apertures, connector ports, and/orother features. The extrusions can have thicknesses of from about onemillimeter to about six millimeters, or from about two millimeters toabout three millimeters. Additionally, each of the apertures can bedefined by a sidewall or web that has a width of from about 0.1millimeter to about 1 millimeter, or about 0.2 millimeter to about 0.5millimeter, or about 0.3 millimeter. In some embodiments, the aperturescan shaped and sized so that the perforated portions 118, 120 and 122are from 75% to 90% open, or from about 79% to about 86% open, or about82% open, for efficient air flow into the cabinet 102 for cooling theinternal components. As noted above, in some embodiments the face panels130, 132 and 134 can be formed from extruded aluminum that is machinedto provide the plurality of apertures in the perforated portions 118,120 and 122. One such product is referred to as MicroVent® and isprovided by Atrenne Computing Solutions of 10 Mupac Drive, Brockton, Me.02301. In other embodiments, other materials can be used to provide thevented face panels 130, 132, and 134.

Turning next to FIG. 1B, each of the fan units 124 includes a perforatedcover 126. The perforated covers 126 can be made from the same materialas the perforated face panels 118, 120 and 122 described above withreference to FIG. 1A. In operation, the fan units 124 are operable todraw ambient cooling air into the cabinet 102 via the air inlets formedby the perforated portions of the face panels 118, 120 and 122 at thefront end 104. As described in greater detail below, the cabinet 102lacks a backplane or midplane oriented perpendicular to the air flowthrough the cabinet, and as a result, the air flows in a generallyunobstructed, linear path through the cabinet 102 before exiting throughthe perforated covers 126 of the fan units 124. This, combined with therelatively high percentage of open area (e.g., 82%-86% open) of the airinlets and outlets, can result in relatively low operating temperaturesfor the internal switch components, which in turn can increase operatingspeed and component service life. For example, in some embodiments theseimprovements can result in operating temperatures of between about 50°C. to about 60° C., or about 55° C., as compared to, for example, 70° C.for a typical network switch enclosure.

FIG. 2 is an enlarged isometric view of a front portion of the cabinet102 illustrating one of the first latches 110 a (the “latch 110”) ingreater detail. In the illustrated embodiment, the latch 110 includes ahandle 220 pivotally coupled to the first line card 108 a proximate tothe left side of the face panel 130. As described in greater detailbelow, the handle 220 can be manipulated by a user to insert the linecard 108 a into the cabinet 102 and secure the line card 108 a inposition by engaging the latch 110 with a structural member (e.g., aside rail 224) on the cabinet 102. When the line card 108 a is fullyinstalled, the handle 220 can be locked in a “closed” position (as shownin FIG. 2) by means of a locking feature on the handle 220 thatreleasably engages a bracket 222 fixedly attached to the face panel 130.To remove the line card 108 a, the user can depress a release actuatorin the form of a button 226, which automatically rotates the handle 220away from the cabinet 102 as indicated by the arrow R to disengage thelatch 110 from the rail 224 and partially eject the line card 108 a. Theuser can then withdraw the line card 108 a from the cabinet 102.

FIG. 3A is an isometric view, and FIGS. 3B-3D are a series of partiallyexploded isometric views, of the latch 110 configured in accordance withan embodiment of the present technology. Referring to FIGS. 3A-30together, the handle 220 is pivotally coupled to a base fitting 330 viaa pivot pin 332. As noted above with reference to FIG. 2, the basefitting 330 is fixedly attached to the outer edge portion of the linecard 108 a. A torsional biasing member 344 (e.g., a torsion spring) isoperably coupled between the handle 220 and the bracket 222, and biasesthe handle 220 away from the closed position illustrated and toward anoutward or open position. The distal end portion of the handle 220includes a manual gripping portion 221 and the proximal end portion ofthe handle 220 includes a retention feature 334 in the form of a hookthat extends beneath a heel 360 having a slightly curved or convexsurface. As described in more detail below with reference to FIGS.4A-4E, the bracket 222 carries a cylindrical guide pin 356 thatcooperates with the retention feature 334 to align and engage the linecard 108 a with the computer cabinet 102 when the handle 220 is rotatedtoward the closed position illustrated in FIGS. 2-3D.

The button 226 is housed in a recess behind a removable cover 336, andis biased upwardly via a biasing member 352 (e.g., a coil spring incompression). Downward movement of the button 226 retracts a lockingfeature 338 that is biased outwardly away from the handle 220 and towardthe bracket 222 by means of a biasing member 346 (e.g., a coilcompression spring). More specifically, as shown in FIG. 3C, the button226 includes two angled surfaces 350 extending downwardly therefromwhich are configured to slideably contact opposite end portions of a pin348 that extends transversely through the locking feature 338.

In the illustrated embodiment, the locking feature 338 is a protrudingcylindrical pin or member having a rounded distal end portion configuredto movably extend through an aperture 340 in the cover 336. Referring toFIG. 3D, the bracket 222 includes an angled ramp 354 leading up to acylindrical recess 342. As described in greater detail below, inoperation the rounded end portion of the locking feature 338 first makescontact with the ramp 354 when the handle 220 is rotated inwardly (i.e.,opposite to the direction indicated by the arrow R in FIG. 2) from thefull open position. As the handle 220 continues to rotate inwardlytoward the position shown in FIG. 3A, the locking feature 338 travels upthe ramp 354 toward the recess 342. Because the ramp 354 is angledtoward the handle 220, as the locking feature 338 slides up the ramp354, it is also driven inwardly toward the handle 220 against thebiasing member 346. However, once the handle 220 is in the fully closedposition shown in FIG. 3A, the locking feature 338 is aligned with therecess 342 and the biasing member 346 drives the rounded end portion ofthe locking feature 338 into the recess 342 to lock the handle 220 inthe closed position. In some embodiments, the handle 220, the basefitting 330, the bracket 223, the guide pin 356, the locking feature 338and/or other elements of the latch 110 can be formed from suitablemetals known in the art, such as aluminum or stainless steel, bymachining, casting, and/or other suitable forming methods known in theart. In other embodiments, other suitable materials, (e.g. plastics,etc.) may be used for one or more of the latch elements describedherein.

Referring to FIG. 3C, to release the handle 220 from the closedposition, a user depresses the button 226 in the downwardly direction Dagainst the biasing member 352. As the button 226 moves downwardly, theangled surfaces 350 bear against the pin 348 and drive the lockingfeature 338 inwardly toward the handle 220 against the biasing member346, thereby extracting the distal end portion of the locking feature338 from the recess 342 and allowing the torsional biasing member 344 toautomatically rotate the gripping portion 221 of the handle 220outwardly toward the open position. As this happens, the heel 360 of thehandle 220 rotates into contact with the rail 224 and pries against therail 224 to automatically push the latch 110 away from the rail 224 andpartially eject the line card 108 a from the cabinet 102.

FIGS. 4A-4E are a series of isometric views illustrating use of thelatch 110 to install a line card (e.g., the line card 108 a) in thecabinet 102 in accordance with an embodiment of the present technology.Referring first to FIG. 4A, the line card 108 a includes a chassis 468that supports the face panel 130 and a circuit board 464 which carriesassociated electronic components and circuitry. Both the bracket 222 andthe base fitting 330 are fixedly attached to the chassis 468 proximatethe left edge of the face panel 130. In the illustrated embodiment, thebracket 222 and the base fitting 330 are separate components. However,in other embodiments, the bracket 222 and the base fitting 330 can beportions of a unitary component.

In FIG. 4A, the line card 108 a is partially inserted into the cabinet102. To fully install the line card 108 a, the user can depress thebutton 226 to disengage the locking feature 338 (FIG. 3B) from therecess 342 in the bracket 222, thereby allowing the handle 220 to rotateoutwardly to the open position shown in FIG. 4B. The user can then pushthe line card 108 a into the cabinet 102 via the handle 220 until thenose of the handle 220 contacts the rail 224 on the side of the cabinet102, as shown in FIG. 40. In this position, the distal end portion ofthe guide pin 356 has just begun to extend through a corresponding guidehole 460 in the rail 224. From the position shown in FIG. 4C, the userrotates the gripping portion 221 of the handle 220 inwardly as indicatedby arrow C. This drives the hook 334 (FIG. 3A) underneath an edgeportion 470 of the rail 224 until the upper surface of the hook 334contacts the underside of the edge portion 470. Continued inwardrotation of the handle 220 as shown in FIG. 4D causes the hook 334 topry against the edge portion 470, which in turn drives the guide pin 356further into the aperture 460 and brings the line card 108 into thefully installed position shown in FIG. 4E. Full rotation of the grippingportion 221 of the handle 220 to the closed position also drives thedistal end portion of the locking feature 338 into the recess 342 in thebracket 222 (FIG. 3D), thereby locking the handle 220 in the closedposition and securing the line card 108 a in the cabinet 102. To releasethe latch 110 from the closed position, the user depresses the button226 in the downwardly direction D (FIG. 30). This retracts the lockingfeature 338, and allows the torsional biasing member 344 toautomatically rotate the handle 220 outwardly toward the open position,thereby disengaging the hook 334 and driving the heel 360 against therail 224 to eject the line card 108 a from the cabinet 102.

As noted above and as illustrated in FIG. 1A, each line card 108includes a first latch 110 a on one side the line card 108 and a secondlatch 110 b on an opposite side of the line card 108. To release andremove a line card 108 from the cabinet 102, the user can depress thebuttons 226 on each of the latches 110 and rotate the correspondinghandles 220 outwardly to disengage the latches 110 from thecorresponding cabinet structures. The line card 108 can then be fullyremoved by simply pulling outwardly on the latches 110 until the linecard 108 is fully withdrawn from the cabinet 102.

FIGS. 5A and 5B are front and rear isometric views, respectively, of thenetwork switch 100 in which a number of exterior panels have beenremoved from the cabinet 102 for purposes of illustration. Referringfirst to FIG. 5A, as noted above, the network switch 100 includes aplurality of the line cards 108 a-108 d arranged horizontally with oneabove the other. In the illustrated embodiment, each of the line cards108 includes electronic circuitry (e.g., one or more ASICs 588) mountedto a corresponding circuit board 586. As also noted above, the controlmodules 112 are positioned beneath the line cards 108, and are orientedvertically in a side-by-side arrangement. Each of the control modules112 can include at least one CPU mounted to a corresponding circuitboard. As illustrated in FIG. 5A, the line cards 108 and the controlmodules 112 are arranged in edgewise orientation relative to the airflow through the computer cabinet 102 as indicated by the arrow A. Asused herein, the term “edgewise orientation” means that the planercircuit board surfaces of the corresponding line cards 108 and controlmodules 112, for example, are oriented with an edge facing the air flowthrough the cabinet, so that their planer circuit board surfaces will beparallel to the air flow through the cabinet, as opposed to beingoriented perpendicularly relative to the air flow as would be the casefor a conventional backplane or midplane.

Referring to FIGS. 5A and 5B together, the aft portion of the cabinet102 contains a plurality of fabric cards 576 (identified individually asfabric cards 576 a-d) oriented vertically and side-by-side relative toeach other. Each of the fabric cards 576 includes a circuit board 592that carries electronic circuitry (e.g., one or more ASICs 590) thatfunction as switching elements to route data from the line cards 108through the network switch. An aft-edge portion of each of the fabriccards 576 can carry a fan control board for providing electrical powerand control to each of the corresponding fan trays. Like the line cards108 and control modules 112 described above, the fabric cards 576 arealso positioned in edgewise orientation relative to the air flow throughthe cabinet 102. Additionally, as can be seen by reference to FIGS. 5Aand 5B, the line cards 108 are orthogonally arranged relative to thecontrol modules 112 and the fabric cards 576.

In the illustrated embodiment, the network switch 100 further includes aleft vertical control plane (VCP) 572 a and a right VCP 572 b (the rightVCP 572 b is omitted from FIG. 5B for purposes of clarity) operablyconnected to a horizontal control plane (HCP) 574 at a mid-frame 570.These components are better seen in FIG. 6A, which is an enlargedisometric view of the assembly of the left and right VCPs 572 and thehorizontal HCP 574, and in FIG. 6B, which is a front view of the cabinet102 with many of the electronic components removed for purposes ofillustration. Referring first to FIG. 6A, the left VCP 572 a includes aplurality of line card connectors 686 (identified individually as linecard connectors 686 a-d) mounted to a front edge portion thereof, andthe right VCP 572 b includes a similar arrangement of line cardconnectors 686 e-686 f. As illustrated in FIG. 5A, each of the linecards 108 includes a left VCP connector 580 a and right VCP connector580 b. Each of the left and right VCP connectors 580 is operablyconnected to a corresponding one of the line card connectors 686 on thecorresponding left or right VCP 572.

Returning to FIG. 6A, the HCP 574 includes a plurality of control moduleconnectors 682 (identified individually as control module connectors 682a-j) mounted to a front edge portion thereof. As illustrated in FIG. 5B,each of the control module connectors 682 is operably connected to acorresponding HCP connector on an aft end of each of the control modules112 a-j. As discussed above, in some embodiments the switch 100 has adisaggregated architecture in which the CPU's for control of the ASICson the line cards 108 and the fabric cards 576 are mounted to thecontrol modules 112, instead of being mounted to the line cards 108and/or the fabric cards 576. One advantage of this architecture is thatthe control modules 112 can be individually removed from the cabinet 102if needed to upgrade the CPUs (by, for example, withdrawing the controlmodules 112 from the front end of the cabinet 102 and disconnecting theconnector 682), without having to remove any of the line cards 108 orthe fabric cards 576 and take them out of service. More specifically, insome embodiments, an individual control module 112 can be removed forCPU upgrade while the corresponding line card and/or fabric card that itcontrols remains in service. In such embodiments, when the controlmodule 112 with the upgraded or new CPU is reinstalled in the switch,the CPU informs the switch ASIC on, e.g. the corresponding line card108, and the switch ASIC configures the newly added CPU (e.g., providesrouting tables) and the CPU can take control of the switch ASIC from nowon.

The HCP 574 additionally includes a plurality of fabric card connectors684 (identified individually as fabric card connectors 684 a-d) mountedto an aft-edge portion thereof. As illustrated in FIG. 5B, each of thefabric cards 576 includes a corresponding HCP connector 584 (firstidentified individually as HCP connectors 584 a-d) that is electricallyconnected to a corresponding one of the fabric card connectors 684 onthe HCP 574. In the foregoing manner, the VCPs 572 and the HCP 574 forma control plane of the network switch 100 for interconnecting thevarious computer modules (e.g., for connecting the control modules 112with the line cards 108, the fabric cards 576, etc.) without requiring amidplane or backplane oriented perpendicularly to the air flow throughthe cabinet 102. Accordingly, by providing the U-shaped control planeassembly illustrated in FIG. 6A, a perpendicular midplane or backplanecan be omitted.

In addition to being electrically connected to the vertical controlplanes 572, each of the line cards 108 is directly connected to each ofthe fabric cards 576. More specifically, as shown in FIG. 5A, each ofthe line cards 108 carries four fabric card connectors 581 (identifiedindividually as fabric card connectors 581 a-d). Similarly, as shown inFIG. 5B, each of the fabric cards 576 carries four corresponding linecard connectors 582 (identified individually as line card connectors 582a-d). Each of the fabric card connectors 581 on the line cards 108 isdirectly electrically connected to the corresponding line cardconnectors 582 on each of the fabric cards 576. In the foregoing manner,each of the line cards 108 is in direct electrical communication witheach of the fabric cards 576 in the absence of, for example, anintervening circuit board connection. The direct connection between linecards 108 and the fabric cards 576 can shorten the signal path andimprove the quality of signals exchanged between these components.Additionally, the connectors 581, 582 are sized and positioned to reducethe impact on air flow through the cabinet 102.

As shown in FIG. 6B, the left VCP 572 a is oriented vertically proximatethe left side wall of the cabinet 102, and the right VCP 572 b issimilarly positioned proximate the right side wall of the cabinet 102.The HCP 574 is connected to the bottom of each of the VCPs 572, andextends horizontally across a lower-mid portion of the cabinet 102 inedgewise orientation relative to the air flow through the cabinet 102.The line card connectors 686 are offset to opposite sides of the cabinet102, and the control module connectors 682 are generally positionedbelow the line card connectors 686. The switch 100 further includes ahorizontal bus bar (HBAR) 688 (also shown in FIG. 5A) and a vertical busbar (VBAR) 694. The VBAR 694 extends vertically in a central portion ofthe cabinet 102 proximate the aft edges of the line cards 108, andcarries a plurality of connectors 696 for providing power to the linecards 108. The HBAR 688 extends horizontally across the cabinet 102 andcarries a plurality of connectors 690 which connect to the power units116 for receiving power therefrom. As illustrated in FIG. 6B, each ofthe power units 116 includes a corresponding circuit board 692 orientedhorizontally and parallel to the air flow through the cabinet 102.Accordingly, because the line cards 108 , the fabric cards 576, thecontrol modules 112, and the power units 116 in the illustratedembodiment are positioned parallel to the air flow through the cabinet102 in the absence of either a midplane and/or a backplane orientedperpendicular to the air flow, cooling air can flow through the cabinet102 in a generally linear direction without having to make 90° turns orotherwise be disrupted by a conventional backplane or midplane. As aresult of this efficient air flow, the network switch 100 can operate atsubstantially lower temperatures than conventional network switches. Forexample, in some embodiments, the network switch 100 can operate attemperatures of about 55° C., rather than temperatures of about 70° C.as typically found in conventional network switches and other similarcomputer systems. Although specific circuitry may be described above,those of ordinary skill in the art will recognize that aspects of thepresent technology are not limited to the particular arrangementsillustrated herein, but can be implemented in various other modulararrangements of switch circuitry.

FIG. 7 in the following discussion provide a brief, general descriptionof a suitable computing environment 700 in which the network switch 100can be implemented. In the illustrated embodiment, the switch 100 can beimplemented in a networked environment using logical connections to oneor more remote computers, such as a plurality of client devices 702(identified individually as client devices 702 a-i). The client devices702 can include, for example, personal computers or work stations, etc.having one or more associated processors coupled to one or more userinput devices, data storage devices, etc. The switch 100 can also beoperably connected to one or more servers 704 and/or an associateddatabases 706. In operation, the switch 100 can receive data from one ormore of the client devices 702 and efficiently route or transmit thedata to one or more different devices in the environment 700, or to anadditional remote device via a router 710 and the Internet 708. Aspectsof the disclosed technology, however, are not limited to any particularenvironment, and may be practiced in a variety of other computingenvironments.

Those skilled in the relevant art will appreciate that aspects of thetechnology disclosed herein can be practiced with other communications,data processing, or computer system configurations, including: Internetappliances, hand-held devices (including personal digital assistants(PDAs)), wearable computers, all manner of cellular or mobile phones(including Voice over IP (VoIP) phones), dumb terminals, media players,gaming devices, multi-processor systems, microprocessor-based orprogrammable consumer electronics, set-top boxes, network PCs,mini-computers, mainframe computers, and the like. Indeed, the terms“computer,” “server,” “host,” “host system,” and the like are generallyused interchangeably herein, and refer to any of the above devices andsystems, as well as any data processor. Aspects of the invention can beembodied in a special purpose computer or data processor that isspecifically programmed, configured, or constructed to perform one ormore of the computer-executable instructions explained in detail herein.While aspects of the invention, such as certain functions, are describedas being performed exclusively on a single device, the invention canalso be practiced in distributed environments where functions or modulesare shared among disparate processing devices, which are linked througha communications network, such as a Local Area Network (LAN), Wide AreaNetwork (WAN), or the Internet. In a distributed computing environment,program modules may be located in both local and remote memory storagedevices.

References throughout the foregoing description to features, advantages,or similar language do not imply that all of the features and advantagesthat may be realized with the present technology should be or are in anysingle embodiment of the invention. Rather, language referring to thefeatures and advantages is understood to mean that a specific feature,advantage, or characteristic described in connection with an embodimentis included in at least one embodiment of the present technology. Thus,discussion of the features and advantages, and similar language,throughout this specification may, but do not necessarily, refer to thesame embodiment.

Furthermore, the described features, advantages, and characteristics ofthe present technology may be combined in any suitable manner in one ormore embodiments. One skilled in the relevant art will recognize thatthe present technology can be practiced without one or more of thespecific features or advantages of a particular embodiment. In otherinstances, additional features and advantages may be recognized incertain embodiments that may not be present in all embodiments of thepresent technology. Any patents and applications and other referencesnoted above, including any that may be listed in accompanying filingpapers, are incorporated herein by reference. Aspects of the inventioncan be modified, if necessary, to employ the systems, functions, andconcepts of the various references described above to provide yetfurther implementations of the invention.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense, as opposed to anexclusive or exhaustive sense; that is to say, in the sense of“including, but not limited to.” As used herein, the terms “connected,”“coupled,” or any variant thereof means any connection or coupling,either direct or indirect, between two or more elements; the coupling orconnection between the elements can be physical, logical, or acombination thereof. Additionally, the words “herein,” “above,” “below,”and words of similar import, when used in this application, refer tothis application as a whole and not to any particular portions of thisapplication. Where the context permits, words in the above DetailedDescription using the singular or plural number may also include theplural or singular number respectively. The word “or,” in reference to alist of two or more items, covers all of the following interpretationsof the word: any of the items in the list, all of the items in the list,and any combination of the items in the list.

The above Detailed Description of examples and embodiments of theinvention is not intended to be exhaustive or to limit the invention tothe precise form disclosed above. While specific examples for theinvention are described above for illustrative purposes, variousequivalent modifications are possible within the scope of the invention,as those skilled in the relevant art will recognize. The teachings ofthe invention provided herein can be applied to other systems, notnecessarily the system described above. The elements and acts of thevarious examples described above can be combined to provide furtherimplementations of the invention. Some alternative implementations ofthe invention may include not only additional elements to thoseimplementations noted above, but also may include fewer elements.Further any specific numbers noted herein are only examples: alternativeimplementations may employ differing values or ranges.

While the above description describes various embodiments of theinvention and the best mode contemplated, regardless how detailed theabove text, the invention can be practiced in many ways. Details of thesystem may vary considerably in its specific implementation, while stillbeing encompassed by the present disclosure. As noted above, particularterminology used when describing certain features or aspects of theinvention should not be taken to imply that the terminology is beingredefined herein to be restricted to any specific characteristics,features, or aspects of the invention with which that terminology isassociated. In general, the terms used in the following claims shouldnot be construed to limit the invention to the specific examplesdisclosed in the specification, unless the above Detailed Descriptionsection explicitly defines such terms. Accordingly, the actual scope ofthe invention encompasses not only the disclosed examples, but also allequivalent ways of practicing or implementing the invention under theclaims.

From the foregoing, it will be appreciated that specific embodiments ofthe invention have been described herein for purposes of illustration,but that various modifications may be made without deviating from thespirit and scope of the various embodiments of the invention. Further,while various advantages associated with certain embodiments of theinvention have been described above in the context of those embodiments,other embodiments may also exhibit such advantages, and not allembodiments need necessarily exhibit such advantages to fall within thescope of the invention. Accordingly, the invention is not limited,except as by the appended claims.

Although certain aspects of the invention are presented below in certainclaim forms, the applicant contemplates the various aspects of theinvention in any number of claim forms. Accordingly, the applicantreserves the right to pursue additional claims after filing thisapplication to pursue such additional claim forms, in either thisapplication or in a continuing application.

1. A computer system comprising: a cabinet having a plurality of sidewalls defining an internal volume, an air inlet positioned at a firstend of the cabinet and an air outlet positioned at a second end of thecabinet, opposite the first end; a plurality of first circuit boardsoperably positioned within the internal volume toward the first end ofthe cabinet, wherein the plurality of first circuit boards are orientedparallel to each other; a plurality of second circuit boards operablypositioned within the internal volume toward the second end of thecabinet, wherein the plurality of second circuit boards are orientedparallel to each other and nonparallel to the plurality of first circuitboards and wherein each of the second circuit boards is operablyconnected to at least one of the first circuit boards without either ofthe first or second circuit boards being connected to an interveningcircuit board extending perpendicular to the plurality of side walls ofthe cabinet; a plurality of third circuit boards operably positionedwithin the internal volume toward the first end of the cabinet beneaththe plurality of first circuity boards, wherein the plurality of thirdcircuit boards are oriented parallel to each other and nonparallel tothe plurality of first circuit boards; and at least one air movermounted to the cabinet and configured to move air along an airflow paththrough the internal volume from the air inlet to the air outlet,wherein the plurality of first and second circuit boards are alignedwith the airflow path.
 2. The computer system of claim 1 wherein theairflow path extends in a generally linear direction through the cabinetfrom the air inlet to the air outlet.
 3. The computer system of claim 1wherein the plurality of first and second circuit boards are oriented inedgewise orientation relative to the airflow path.
 4. The computersystem of claim 1 wherein the cabinet lacks a midplane circuit boardextending perpendicular to the side walls of the cabinet.
 5. Thecomputer system of claim 1 wherein the cabinet lacks a backplane circuitboard extending perpendicular to the side walls of the cabinet.
 6. Thecomputer system of claim 1 and wherein the first circuit boards areelectrically connected to the second circuit boards in the absence of athird circuit board oriented perpendicular to the airflow path thoughthe cabinet.
 7. The computer system of claim 1: wherein each of thefirst circuit boards includes a planar surface having electroniccircuitry thereon, wherein each of the second circuit boards includes aplanar surface having electronic circuitry thereon, and wherein theplanar surfaces of the first circuit boards are nonparallel to theplanar surfaces of the second circuit boards.
 8. The computer system ofclaim 1: wherein each of the first circuit boards includes a planarsurface having electronic circuitry thereon, wherein each of the secondcircuit boards includes a planar surface having electronic circuitrythereon, and wherein the planar surfaces of the first circuit boards areperpendicular to the planar surfaces of the second circuit boards. 9.The computer system of claim 1: wherein each of the first circuit boardsincludes electronic circuitry thereon, wherein each of the secondcircuit boards includes electronic circuitry thereon, and wherein theelectronic circuitry on each of the first circuit boards is electricallyconnected to the electronic circuitry on at least one of the secondcircuit boards in the absence of an intermediate circuit boardtherebetween.
 10. The computer system of claim 1: wherein each of thefirst circuit boards includes electronic circuitry thereon, wherein eachof the second circuit boards includes electronic circuitry thereon, andwherein the electronic circuitry on each of the first circuit boards iselectrically connected to the electronic circuitry on at least one ofthe second circuit boards in the absence of an intermediate thirdcircuit board therebetween oriented perpendicular to the airflow paththrough the cabinet.
 11. The computer system of claim 1: wherein each ofthe first circuit boards includes an electrical connector operablymounted to an aft edge portion thereof, wherein each of the secondcircuit boards includes an electrical connector operably mounted to aforward edge portion thereof, and wherein the electrical connector oneach of the first circuit boards is electrically mated to acorresponding electrical connector on at least one of the second circuitboards.
 12. The computer system of claim 1 wherein the plurality offirst and second circuit boards comprise a switch for connectingcomputer devices in a network.
 13. The computer system of claim 1:wherein the plurality of first circuit boards comprises line cards, andwherein the plurality of second circuit boards comprises fabric cards.14. A method for cooling computer modules in a computer system, themethod comprising: positioning a plurality of first computer modulesparallel to each other in a first portion of an enclosure; positioning aplurality of second computer modules parallel to each other in a secondportion of the enclosure; positioning a plurality of third computermodules parallel to each other in a third portion of the enclosure,wherein the plurality of third computer modules are oriented parallel toeach other and nonparallel to the plurality of first computer modules;operably connecting each of the plurality of first computer modules toat least one of the plurality of second computer modules withoutconnecting any of the first or second computer modules to a circuitboard oriented perpendicular to the plurality of first and secondcomputer modules; and directing cooling air through the enclosure alongan airflow path extending parallel to the plurality of first and secondcomputer modules.
 15. The method of claim 14 wherein positioning theplurality of second computer modules parallel includes orienting theplurality of second computer modules orthogonally relative to theplurality of first computer modules.
 16. The method of claim 14, furthercomprising: positioning a circuit board generally between the pluralityof first computer modules and the plurality of second computer modulesand parallel to the airflow path; operably connecting the plurality offirst computer modules to the circuit board; and operably connecting theplurality of second computer modules to the circuit board.
 17. Themethod of claim 16: wherein positioning the plurality of first computermodules includes positioning a plurality of line cards parallel to eachother in a first portion of a network switch; wherein positioning aplurality of second computer modules includes positioning a plurality offabric cards parallel to each other in a second portion of the networkswitch; and wherein operably connecting the plurality of line cards andthe plurality of fabric cards to the circuit board includes operablyconnecting the plurality of line cards and the plurality of fabric cardsto a control plane oriented vertically to one side of the enclosure. 18.The method of claim 16 wherein positioning a circuit board includespositioning a first circuit board to a first side of the enclosure, andwherein the method further comprises: positioning a second circuit boardgenerally between the plurality of first computer modules and theplurality of second computer modules, wherein the second circuit boardis positioned to a second side of the enclosure opposite the first sideand parallel to the airflow path; operably connecting the plurality offirst computer modules to the second circuit board; and operablyconnecting the plurality of second computer modules to the secondcircuit board.
 19. The method of claim 14 wherein the enclosure has afront end and an aft end, wherein directing cooling air through theenclosure includes directing air in a generally straight path from anair inlet at the front end toward an air outlet at the aft end.
 20. Themethod of claim 14 wherein the enclosure has a front end and an aft end,and wherein the method further comprises: positioning at least one fantoward a rear end of the enclosure, wherein directing cooling airthrough the enclosure includes operating the fan to move air into theenclosure through the front end, then over the plurality of firstcomputer modules, then over the plurality of second computer modules,and then out of the enclosure through the aft end.